Connector for cam-actuated switch



NOV. 4, 1969 w LQFSTRAND 3,476,903

CONNECTOR FOR CAM-ACTUATED SWITCH Filed June 24, 1968 1:15 T INVENTOR.

WA'WE/Y 4 ZomsnQ/WD WM Toe V 75 United States Patent M 3,476,903 CONNECTOR FOR CAM-ACTUATED SWITCH Warren A. Lofstrand, Wethersfield, Conn., assignor to The Sessions Clock Co., Forestville, Conn., 21 corporation of Connecticut Filed June 24, 1968, Ser. No. 739,455 Int. Cl. H01h 9/02 US. Cl. 200-168 2 Claims ABSTRACT OF THE DISCLOSURE A connector for a motor-driven, cam-actuated switch enclosed in a housing with contact terminals on the front plate connected to motor-driven switching means by a flexible printed circuit which has an extension for solder connection directly to fixed motor terminals. The front plate of the housing for the switch is a single piece of insulating material and has spaced, integral, internal projections for locating the front plate in predetermined relation in the open end of the housing.

The invention relates to control devices and more particularly to a novel and improved construction of camactuated switch.

Cam-actuated switches of the type with which this invention is used are extensively employed in telephone systems. Because of the great numbers of switches used and because all cost factors for telephone systems are carefully scrutinized by the telephone companies and by governmental bodies involved in guarding public utility charge rates, any cost reduction in these switches is of great importance.

An object of the invention is the provision of a novel and improved housing and connector construction for a device of the type set forth and which is simpler and mechanically stronger than prior devices and yet costs much less than the prior devices.

Another object is to provide a new and improved arrangement for supplying current to the motor of a control device, such as a cam-actuated switch, whereby the current supplying means is combined with the printed circuit system of the device thus simplifying and reducing the cost of the device.

Another object is to provide a cam-actuated switch, of the type set forth, and incorporating improved features whereby a more economical, yet efficient, apparatus is obtained.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will be understood that changes may be made in the details of construction and arrangement of parts shown and described without departing from the spirit of the invention, as the preferred form has been given by way of illustration only.

For a better understanding of the above and other advantageous features of the invention, reference should be made to the following detailed description and to the accompanying drawings in which:

FIG. 1 is a side view, partially in section, of a camactuated switch constructed according to the invention;

FIG. 2 is a fragmentary sectional view of a prior art form of cam-actuated switch;

FIG. 3 is a perspective, exploded view of the apparatus shown in FIG. 1, with the front plate separated from the remainder of the apparatus; and

FIG. 4 is a plan view of the inner surface of the front plate of the apparatus.

The cam-actuated switch in FIG. 1 is an interrupter timer apparatus electrically similar to the timer shown in US. Patent 3,106,620 to A. W. Haydon, and it includes Patented Nov. 4, 1969 a housing 10 having an open end adapted to be closed by a front plate 11 of insulating material held in assembled relation with the' housing 10 by a set of screws 12 positioned in respective openings 13 and extending through channels in respective, integral, support posts 14 on the inner side of the front plate 11. These locating lugs or members 14 of insulating material are integral with the plate 11 and serve both to locate and to support the front plate in the open end of housing 10 relative to an intermediate plate 16 which is in the housing and spaced from the open end thereof. Thus, the plate 11 and the lugs 15 are all combined into a single insulating member. FIG. 4 shows the back surface of the plate 11 with the integral posts 14 and integral strengthening buttresses 15. The front plate, or wall, 11 of the housing 10 carries a set of plugin contacts 17 whereby the unit may be connected to an apparatus with which it is employed by being plugged therein. The contacts 17 have terminal portions 18 extending through the front plate 11 into the interior of the housing 10, as hereinafter described.

FIG. 2 shows the complex connector structure of the prior art which has the same contacts 17 as shown in FIG. 1 arranged in the same pattern but held in a relatively small insulator body 11a which is attached to a separate metal plate 11b by means of a number of rivets 110. The plate 11b is attached to the remainder of the switch mechanism of the same type shown in FIG. 1 by means of the same screws 12 but some type of spacer must also be added to take the place of the integral support posts 14 of FIG. 1. Thus it may be seen that the structure in FIG. 2 is much more complex than the plate 11 in FIG. 1 and at the same time there is a shorter distance between any of the contacts 17 and the plate 11b than there is between the contacts 17 in FIG. 1 and the screws 12 so that there is a greater danger of electrical leakage from the contacts via the plate 11b to the rest of the switch mechanism for the embodiment of FIG. 2 than there is for the mechanism of the invention as shown in FIG. 1. There is a reduction in cost of about 50% for the components alone of the plate 11 of FIG. 1 versus the complex parts shown in FIG. 2. In addition to the lower component cost, assembly is also simplified and the labor cost further reduces the overall cost of the complete switch.

Within the housing 10, at the end opposite the front plate 11, is positioned a motor 19, which may be a governed or synchronous, constant speed motor mounted on an inner plate, or deck, 20 and having an output shaft that projects through the plate 20 and is operatively connected to a conventional cam-actuated switch 21, which may be of any desired type, although, as stated, the particular switch mechanism shown is the same as that described in US. Patent 3,106,620. The motor 19 has the terminals 22, and the switch 21 has switch arms 23 provided with terminals 24 that extend generally parallel to the terminals 22.

For electrical connection of the contact terminals 18 on the front plate 11 with respective ones of the terminals 24 and with the motor terminals 22, there is provided a member 25 in the form of a flexible strip of insulating material having a printed circuit 26 on the surface thereof to provide the desired electrical connections. The printed circuits 26 connect the contact terminals 18 to the correct switch terminals 24 and are joined to the terminals 18 by solder connections 27 to the terminals 24 by additional solder connections 28, For supplying current to the motor 19, one end of the printed circuit member 25 is provided with an extension 29 for carrying the motor circuit to the terminals 22 of the motor 19, to which it is connected by a solder connection 30. Such an arrangement permits a less expensive motor to be used and eliminates the necessity of special flexible cables for the motor circuit and,

also, provides a much more economical and trouble-free construction since all connections, both to' the switch 21 and the motor 19 may be made in the same way and without any danger of reversing or short-circuiting the connections.

The invention that is claimed is:

1. In a cam-actuated switch, a housing having an open end; a front wall ofinsulating material closing the open end, said front wall having plug-in contacts on its outer side and contact terminals on its inner side and spaced, integral, internal projections for locating said front wall in pre-determined relation to said housing; a motor in said housing, said motor comprising fixed terminals; switching means in said housing intermediate said motor and front wall and operatively connected to said motor; a flexible member carrying printed circuits for electrical connection of said contact terminals on said front wall with contact terminals for the switching means, said printed circuit means comprising direct electrical connections from said motor terminals to predetermined ones of said contact terminals.

2. A cam-actuated switch as claimed in claim 1, wherein openings for fastening means are provided through each of said internal projections on said front plate; and fastening means are positioned in each of said openings for securing said front plate in operative position on said 10 housing.

References Cited UNITED STATES PATENTS 2,952,755 9/1960 Brinker et a1. 335-202 XR 3,106,620 10/ 1963 Haydon. 3,311,718 3/1967 Allison et a1.

H. O. JONES, Primary Examiner 

